Which of the following is a factor of 15 + 7x – 2x2
-
A.
x + 3 -
B.
x – 3 -
C.
x – 5 -
D.
x + 5
Correct Answer: Option C
Explanation
Factorize 15 + 7x – 2x2
(5 – x)(3 + 2x); suppose 15 + 7x = 2x2 = 0
∴ (5 – x)(3 + 2x) = 0
x = 5 or x = -(frac{3}{2})
Since 5 is a root, then (x – 5) is a factor